The first review of Wicket in Action is on Amazon.com! Dan Syrstad (known from Wicket Web Beans) responded to my plight for reviews in the following way:
This is a great book that really gives a in-depth overview of Wicket. I've been working with Wicket for a couple of years and had to suffer through figuring things out from examples and mailing lists. This book is the definitive guide. I've already learned several new things from it. Many thanks to the authors who went to great lengths to get this book out!
Let me thank Dan for writing this review. We really appreciate it!